Periodic and aperiodic csi reporting procedures for enhanced licensed assisted access

ABSTRACT

In enhanced licensed assisted access (eLAA), providing several approaches to report the CSI measurement may be desirable to provide flexibility in CSI reporting, especially in aperiodic CSI reporting. Further, a difference in using a licensed carrier and an unlicensed carrier may be considered during communication. In addition, assigning different transmit power usage based on different transmission types may be desired. The apparatus may be a user equipment (UE). The apparatus may be a UE. The UE receives a grant for uplink communication. The UE determines a reporting subframe based on the grant. The UE determines whether to select, as a reference subframe, a triggering subframe in which the grant is received or a subframe before the reporting subframe. The UE transmits, in the reporting subframe, channel state information (CSI) measured in the reference subframe.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation of U.S. application Ser. No.15/461,280, entitled “PERIODIC AND APERIODIC CSI REPORTING PROCEDURESFOR ENHANCED LICENSED ASSISTED ACCESS” and filed on Mar. 16, 2017, whichclaims the benefit of U.S. Provisional Application Ser. No. 62/372,264,entitled “PERIODIC AND APERIODIC CSI REPORTING PROCEDURES FOR ENHANCEDLICENSED ASSISTED ACCESS” and filed on Aug. 8, 2016, the entire contentsof both of which are expressly incorporated by reference herein in theirentirety.

BACKGROUND Field

The present disclosure relates generally to communication systems, andmore particularly, to measurement and reporting of channel quality, andpower control for transmitting channel quality reports.

Background

Wireless communication systems are widely deployed to provide varioustelecommunication services such as telephony, video, data, messaging,and broadcasts. Typical wireless communication systems may employmultiple-access technologies capable of supporting communication withmultiple users by sharing available system resources. Examples of suchmultiple-access technologies include code division multiple access(CDMA) systems, time division multiple access (TDMA) systems, frequencydivision multiple access (FDMA) systems, orthogonal frequency divisionmultiple access (OFDMA) systems, single-carrier frequency divisionmultiple access (SC-FDMA) systems, and time division synchronous codedivision multiple access (TD-SCDMA) systems.

These multiple access technologies have been adopted in varioustelecommunication standards to provide a common protocol that enablesdifferent wireless devices to communicate on a municipal, national,regional, and even global level. An example telecommunication standardis Long Term Evolution (LTE). LTE is a set of enhancements to theUniversal Mobile Telecommunications System (UMTS) mobile standardpromulgated by Third Generation Partnership Project (3GPP). LTE isdesigned to support mobile broadband access through improved spectralefficiency, lowered costs, and improved services using OFDMA on thedownlink, SC-FDMA on the uplink, and multiple-input multiple-output(MIMO) antenna technology. However, as the demand for mobile broadbandaccess continues to increase, there exists a need for furtherimprovements in LTE technology. These improvements may also beapplicable to other multi-access technologies and the telecommunicationstandards that employ these technologies.

SUMMARY

The following presents a simplified summary of one or more aspects inorder to provide a basic understanding of such aspects. This summary isnot an extensive overview of all contemplated aspects, and is intendedto neither identify key or critical elements of all aspects nordelineate the scope of any or all aspects. Its sole purpose is topresent some concepts of one or more aspects in a simplified form as aprelude to the more detailed description that is presented later.

In enhanced licensed assisted access (eLAA), measuring and reporting ofchannel state information (CSI) may be based on an uplink grant andother signaling. A user equipment (UE) may report the measured CSI viaperiodic CSI reporting and/or aperiodic CSI reporting. Providing severalapproaches to report the CSI measurement may be desirable to provideflexibility in CSI reporting, especially in aperiodic CSI reporting.Further, a difference in using a licensed carrier and an unlicensedcarrier may be considered during communication. In addition, differenttransmissions may be assigned with different priorities to scale UEtransmit power usage.

In an aspect of the disclosure, a method, a computer-readable medium,and an apparatus are provided. The apparatus may be a UE for wirelesscommunication in a shared spectrum. The UE receives a grant for uplinkcommunication. The UE determines a reporting subframe based on thegrant. The UE determines whether to select, as a reference subframe, atriggering subframe in which the grant is received or a subframe beforethe reporting subframe. The UE transmits, in the reporting subframe, CSImeasured in the reference subframe.

In an aspect, the apparatus may be a UE for wireless communication in ashared spectrum. The UE may include means for receiving a grant foruplink communication. The UE may include means for determining areporting subframe based on the grant. The UE may include means fordetermining whether to select, as a reference subframe, a triggeringsubframe in which the grant is received or a subframe before thereporting subframe. The UE may include means for transmitting, in thereporting subframe, CSI measured in the reference subframe.

In an aspect, the apparatus may be a UE for wireless communication in ashared spectrum, where the UE may include a memory and at least oneprocessor coupled to the memory. The at least one processor may beconfigured to: receive a grant for uplink communication, determine areporting subframe based on the grant, determine whether to select, as areference subframe, a triggering subframe in which the grant is receivedor a subframe before the reporting subframe, and transmit, in thereporting subframe, CSI measured in the reference subframe.

In an aspect, a computer-readable medium storing computer executablecode for a UE for wireless communication in a shared spectrum mayinclude code to: receive a grant for uplink communication, determine areporting subframe based on the grant, determine whether to select, as areference subframe, a triggering subframe in which the grant is receivedor a subframe before the reporting subframe, and transmit, in thereporting subframe, CSI measured in the reference subframe.

In another aspect of the disclosure, a method, a computer-readablemedium, and an apparatus are provided. The apparatus may be a UE forwireless communication in a shared spectrum. The UE determines a cellgroup, the cell group including at least one licensed carrier configuredwith an uplink control channel and one or more unlicensed carriers. TheUE reports at least one of a hybrid automatic repeat request (HARQ)acknowledgement/negative-acknowledgement (ACK/NACK) or periodic CSI forthe cell group on the at least one licensed carrier provided by the cellgroup.

In an aspect, the apparatus may be a UE for wireless communication in ashared spectrum. The UE may include means for determining a cell group,the cell group including at least one licensed carrier configured withan uplink control channel and one or more unlicensed carriers. The UEmay include means for reporting at least one of a HARQ ACK/NACK orperiodic CSI for the cell group on the at least one licensed carrierprovided by the cell group.

In an aspect, the apparatus may be a UE for wireless communication in ashared spectrum, where the UE may include a memory and at least oneprocessor coupled to the memory. The at least one processor may beconfigured to: determine a cell group, the cell group including at leastone licensed carrier configured with an uplink control channel and oneor more unlicensed carriers, and report at least one of a HARQ ACK/NACKor periodic CSI for the cell group on the at least one licensed carrierprovided by the cell group.

In an aspect, a computer-readable medium storing computer executablecode for a UE for wireless communication in a shared spectrum mayinclude code to: determine a cell group, the cell group including atleast one licensed carrier configured with an uplink control channel andone or more unlicensed carriers, and report at least one of a HARQACK/NACK or periodic CSI for the cell group on the at least one licensedcarrier provided by the cell group.

In another aspect of the disclosure, a method, a computer-readablemedium, and an apparatus are provided. The apparatus may be a UE forwireless communication in a shared spectrum. The UE determines a firstcell group including one or more licensed carriers. The UE determines asecond cell group including one of more unlicensed carriers. The UEreceives a CSI trigger. The UE transmits the CSI on a licensed carrierin the first cell group if the CSI trigger was received on a firstcarrier in the first cell group. The UE transmits the CSI on anunlicensed carrier in the second cell group if the CSI trigger wasreceived on a second carrier in the second cell group.

In an aspect, the apparatus may be a UE for wireless communication in ashared spectrum. The UE may include means for determining a first cellgroup including one or more licensed carriers. The UE may include meansfor determining a second cell group including one of more unlicensedcarriers. The UE may include receiving a CSI trigger. The UE may includemeans for transmitting the CSI on a licensed carrier in the first cellgroup if the CSI trigger was received on a first carrier in the firstcell group. The UE may include means for transmitting the CSI on anunlicensed carrier in the second cell group if the CSI trigger wasreceived on a second carrier in the second cell group.

In an aspect, the apparatus may be a UE for wireless communication in ashared spectrum, where the UE may include a memory and at least oneprocessor coupled to the memory. The at least one processor may beconfigured to: determine a first cell group including one or morelicensed carriers, determine a second cell group including one of moreunlicensed carriers, receive a CSI trigger, transmit the CSI on alicensed carrier in the first cell group if the CSI trigger was receivedon a first carrier in the first cell group, and transmit the CSI on anunlicensed carrier in the second cell group if the CSI trigger wasreceived on a second carrier in the second cell group.

In an aspect, a computer-readable medium storing computer executablecode for a UE for wireless communication in a shared spectrum mayinclude code to: determine a first cell group including one or morelicensed carriers, determine a second cell group including one of moreunlicensed carriers, receive a CSI trigger, transmit the CSI on alicensed carrier in the first cell group if the CSI trigger was receivedon a first carrier in the first cell group, and transmit the CSI on anunlicensed carrier in the second cell group if the CSI trigger wasreceived on a second carrier in the second cell group.

In another aspect of the disclosure, a method, a computer-readablemedium, and an apparatus are provided. The apparatus may be a UE forwireless communication in a shared spectrum. The UE allocates a firstportion of a total transmit power to transmission of an uplink controlinformation to a licensed serving cell via an uplink channel on alicensed carrier. The UE allocates a second portion of the totaltransmit power to transmission of an aperiodic CSI on an unlicensedcarrier to an unlicensed cell, where the second portion is less than orequal to remaining portion of the total transmit power after allocatingthe first portion to the uplink channel.

In an aspect, the apparatus may be a UE for wireless communication in ashared spectrum. The UE may include means for allocating a first portionof a total transmit power to transmission of an uplink controlinformation to a licensed serving cell via an uplink channel on alicensed carrier. The UE may include means for allocating a secondportion of the total transmit power to transmission of an aperiodic CSIon an unlicensed carrier to an unlicensed cell, where the second portionis less than or equal to remaining portion of the total transmit powerafter allocating the first portion to the uplink channel.

In an aspect, the apparatus may be a UE for wireless communication in ashared spectrum, where the UE may include a memory and at least oneprocessor coupled to the memory. The at least one processor may beconfigured to: allocate a first portion of a total transmit power totransmission of an uplink control information to a licensed serving cellvia an uplink channel on a licensed carrier, and allocate a secondportion of the total transmit power to transmission of an aperiodic CSIon an unlicensed carrier to an unlicensed cell, where the second portionis less than or equal to remaining portion of the total transmit powerafter allocating the first portion to the uplink channel.

In an aspect, a computer-readable medium storing computer executablecode for a UE for wireless communication in a shared spectrum mayinclude code to: allocate a first portion of a total transmit power totransmission of an uplink control information to a licensed serving cellvia an uplink channel on a licensed carrier, and allocate a secondportion of the total transmit power to transmission of an aperiodic CSIon an unlicensed carrier to an unlicensed cell, where the second portionis less than or equal to remaining portion of the total transmit powerafter allocating the first portion to the uplink channel.

To the accomplishment of the foregoing and related ends, the one or moreaspects comprise the features hereinafter fully described andparticularly pointed out in the claims. The following description andthe annexed drawings set forth in detail certain illustrative featuresof the one or more aspects. These features are indicative, however, ofbut a few of the various ways in which the principles of various aspectsmay be employed, and this description is intended to include all suchaspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating an example of a wireless communicationssystem and an access network.

FIGS. 2A, 2B, 2C, and 2D are diagrams illustrating LTE examples of a DLframe structure, DL channels within the DL frame structure, an UL framestructure, and UL channels within the UL frame structure, respectively.

FIG. 3 is a diagram illustrating an example of an evolved Node B (eNB)and user equipment (UE) in an access network.

FIG. 4 is an example timeline diagram illustrating channel stateinformation measurement and reporting.

FIGS. 5A and 5B are example diagrams illustrating channel stateinformation (CSI) measurement in a reference subframe and CSI reportingin a reporting subframe, according to an aspect of the disclosure.

FIGS. 6A and 6B are example diagrams illustrating CSI measurement in areference subframe and CSI reporting in a reporting subframe, accordingto another aspect of the disclosure.

FIG. 7 is an example diagram illustrating channel state informationmeasurement and reporting based on multiple transmission time intervalgrants.

FIG. 8 is a flowchart of a method of wireless communication, accordingto an aspect of the disclosure.

FIG. 9 is a flowchart of a method of wireless communication, accordingto another aspect of the disclosure.

FIG. 10 is a flowchart of a method of wireless communication, accordingto another aspect of the disclosure.

FIG. 11 is a flowchart of a method of wireless communication, accordingto another aspect of the disclosure.

FIG. 12 is a conceptual data flow diagram illustrating the data flowbetween different means/components in an exemplary apparatus.

FIG. 13 is a diagram illustrating an example of a hardwareimplementation for an apparatus employing a processing system.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appendeddrawings is intended as a description of various configurations and isnot intended to represent the only configurations in which the conceptsdescribed herein may be practiced. The detailed description includesspecific details for the purpose of providing a thorough understandingof various concepts. However, it will be apparent to those skilled inthe art that these concepts may be practiced without these specificdetails. In some instances, well known structures and components areshown in block diagram form in order to avoid obscuring such concepts.

Several aspects of telecommunication systems will now be presented withreference to various apparatus and methods. These apparatus and methodswill be described in the following detailed description and illustratedin the accompanying drawings by various blocks, components, circuits,processes, algorithms, etc. (collectively referred to as “elements”).These elements may be implemented using electronic hardware, computersoftware, or any combination thereof. Whether such elements areimplemented as hardware or software depends upon the particularapplication and design constraints imposed on the overall system.

By way of example, an element, or any portion of an element, or anycombination of elements may be implemented as a “processing system” thatincludes one or more processors. Examples of processors includemicroprocessors, microcontrollers, graphics processing units (GPUs),central processing units (CPUs), application processors, digital signalprocessors (DSPs), reduced instruction set computing (RISC) processors,systems on a chip (SoC), baseband processors, field programmable gatearrays (FPGAs), programmable logic devices (PLDs), state machines, gatedlogic, discrete hardware circuits, and other suitable hardwareconfigured to perform the various functionality described throughoutthis disclosure. One or more processors in the processing system mayexecute software. Software shall be construed broadly to meaninstructions, instruction sets, code, code segments, program code,programs, subprograms, software components, applications, softwareapplications, software packages, routines, subroutines, objects,executables, threads of execution, procedures, functions, etc., whetherreferred to as software, firmware, middleware, microcode, hardwaredescription language, or otherwise.

Accordingly, in one or more example embodiments, the functions describedmay be implemented in hardware, software, or any combination thereof. Ifimplemented in software, the functions may be stored on or encoded asone or more instructions or code on a computer-readable medium.Computer-readable media includes computer storage media. Storage mediamay be any available media that can be accessed by a computer. By way ofexample, and not limitation, such computer-readable media can comprise arandom-access memory (RAM), a read-only memory (ROM), an electricallyerasable programmable ROM (EEPROM), optical disk storage, magnetic diskstorage, other magnetic storage devices, combinations of theaforementioned types of computer-readable media, or any other mediumthat can be used to store computer executable code in the form ofinstructions or data structures that can be accessed by a computer.

FIG. 1 is a diagram illustrating an example of a wireless communicationssystem and an access network 100. The wireless communications system(also referred to as a wireless wide area network (WWAN)) includes basestations 102, UEs 104, and an Evolved Packet Core (EPC) 160. The basestations 102 may include macro cells (high power cellular base station)and/or small cells (low power cellular base station). The macro cellsinclude eNBs. The small cells include femtocells, picocells, andmicrocells.

The base stations 102 (collectively referred to as Evolved UniversalMobile

Telecommunications System (UMTS) Terrestrial Radio Access Network(E-UTRAN)) interface with the EPC 160 through backhaul links 132 (e.g.,S1 interface). In addition to other functions, the base stations 102 mayperform one or more of the following functions: transfer of user data,radio channel ciphering and deciphering, integrity protection, headercompression, mobility control functions (e.g., handover, dualconnectivity), inter-cell interference coordination, connection setupand release, load balancing, distribution for non-access stratum (NAS)messages, NAS node selection, synchronization, radio access network(RAN) sharing, multimedia broadcast multicast service (MBMS), subscriberand equipment trace, RAN information management (RIM), paging,positioning, and delivery of warning messages. The base stations 102 maycommunicate directly or indirectly (e.g., through the EPC 160) with eachother over backhaul links 134 (e.g., X2 interface). The backhaul links134 may be wired or wireless.

The base stations 102 may wirelessly communicate with the UEs 104. Eachof the base stations 102 may provide communication coverage for arespective geographic coverage area 110. There may be overlappinggeographic coverage areas 110. For example, the small cell 102′ may havea coverage area 110′ that overlaps the coverage area 110 of one or moremacro base stations 102. A network that includes both small cell andmacro cells may be known as a heterogeneous network. A heterogeneousnetwork may also include Home Evolved Node Bs (eNBs) (HeNBs), which mayprovide service to a restricted group known as a closed subscriber group(CSG). The communication links 120 between the base stations 102 and theUEs 104 may include uplink (UL) (also referred to as reverse link)transmissions from a UE 104 to a base station 102 and/or downlink (DL)(also referred to as forward link) transmissions from a base station 102to a UE 104. The communication links 120 may use MIMO antennatechnology, including spatial multiplexing, beamforming, and/or transmitdiversity. The communication links may be through one or more carriers.The base stations 102/UEs 104 may use spectrum up to Y MHz (e.g., 5, 10,15, 20 MHz) bandwidth per carrier allocated in a carrier aggregation ofup to a total of Yx MHz (x component carriers) used for transmission ineach direction. The carriers may or may not be adjacent to each other.Allocation of carriers may be asymmetric with respect to DL and UL(e.g., more or less carriers may be allocated for DL than for UL). Thecomponent carriers may include a primary component carrier and one ormore secondary component carriers. A primary component carrier may bereferred to as a primary cell (PCell) and a secondary component carriermay be referred to as a secondary cell (SCell).

The wireless communications system may further include a Wi-Fi accesspoint (AP) 150 in communication with Wi-Fi stations (STAs) 152 viacommunication links 154 in a 5 GHz unlicensed frequency spectrum. Whencommunicating in an unlicensed frequency spectrum, the STAs 152/AP 150may perform a clear channel assessment (CCA) prior to communicating inorder to determine whether the channel is available.

The small cell 102′ may operate in a licensed and/or an unlicensedfrequency spectrum. When operating in an unlicensed frequency spectrum,the small cell 102′ may employ LTE and use the same 5 GHz unlicensedfrequency spectrum as used by the Wi-Fi AP 150. The small cell 102′,employing LTE in an unlicensed frequency spectrum, may boost coverage toand/or increase capacity of the access network. LTE in an unlicensedspectrum may be referred to as LTE-unlicensed (LTE-U), licensed assistedaccess (LAA), or MuLTEfire.

The millimeter wave (mmW) base station 180 may operate in mmWfrequencies and/or near mmW frequencies. Extremely high frequency (EHF)is part of the RF in the electromagnetic spectrum. EHF has a range of 30GHz to 300 GHz and a wavelength between 1 millimeter and 10 millimeters.Radio waves in the band may be referred to as a millimeter wave. NearmmW may extend down to a frequency of 3 GHz with a wavelength of 100millimeters. The super high frequency (SHF) band extends between 3 GHzand 30 GHz, also referred to as centimeter wave. Communications usingthe mmW/near mmW radio frequency band has extremely high path loss and ashort range. The mmW base station 180 may utilize beamforming 184 tocompensate for the extremely high path loss and short range whencommunicating with UE 182.

The EPC 160 may include a Mobility Management Entity (MME) 162, otherMMEs 164, a Serving Gateway 166, a Multimedia Broadcast MulticastService (MBMS) Gateway 168, a Broadcast Multicast Service Center (BM-SC)170, and a Packet Data Network (PDN) Gateway 172. The MME 162 may be incommunication with a Home Subscriber Server (HSS) 174. The MME 162 isthe control node that processes the signaling between the UEs 104 andthe EPC 160. Generally, the MME 162 provides bearer and connectionmanagement. All user Internet protocol (IP) packets are transferredthrough the Serving Gateway 166, which itself is connected to the PDNGateway 172. The PDN Gateway 172 provides UE IP address allocation aswell as other functions. The PDN Gateway 172 and the BM-SC 170 areconnected to the IP Services 176. The IP Services 176 may include theInternet, an intranet, an IP Multimedia Subsystem (IMS), a PS StreamingService (PSS), and/or other IP services. The BM-SC 170 may providefunctions for MBMS user service provisioning and delivery. The BM-SC 170may serve as an entry point for content provider MBMS transmission, maybe used to authorize and initiate MBMS Bearer Services within a publicland mobile network (PLMN), and may be used to schedule MBMStransmissions. The MBMS Gateway 168 may be used to distribute MBMStraffic to the base stations 102 belonging to a Multicast BroadcastSingle Frequency Network (MBSFN) area broadcasting a particular service,and may be responsible for session management (start/stop) and forcollecting eMBMS related charging information.

The base station may also be referred to as a Node B, evolved Node B(eNB), an access point, a base transceiver station, a radio basestation, a radio transceiver, a transceiver function, a basic serviceset (BSS), an extended service set (ESS), or some other suitableterminology. The base station 102 provides an access point to the EPC160 for a UE 104. Examples of UEs 104 include a cellular phone, a smartphone, a session initiation protocol (SIP) phone, a laptop, a personaldigital assistant (PDA), a satellite radio, a global positioning system,a multimedia device, a video device, a digital audio player (e.g., MP3player), a camera, a game console, a tablet, a smart device, a wearabledevice, or any other similar functioning device. The UE 104 may also bereferred to as a station, a mobile station, a subscriber station, amobile unit, a subscriber unit, a wireless unit, a remote unit, a mobiledevice, a wireless device, a wireless communications device, a remotedevice, a mobile subscriber station, an access terminal, a mobileterminal, a wireless terminal, a remote terminal, a handset, a useragent, a mobile client, a client, or some other suitable terminology.

Referring again to FIG. 1, in certain aspects, the UE 104 may beconfigured to determine a way to measure and report the CSI based on anuplink grant, may be configured to utilize licensed carriers andunlicensed carriers different, and may be configured to scale UEtransmit power based on transmission types (198).

FIG. 2A is a diagram 200 illustrating an example of a DL frame structurein LTE. FIG. 2B is a diagram 230 illustrating an example of channelswithin the DL frame structure in LTE. FIG. 2C is a diagram 250illustrating an example of an UL frame structure in LTE. FIG. 2D is adiagram 280 illustrating an example of channels within the UL framestructure in LTE. Other wireless communication technologies may have adifferent frame structure and/or different channels. In LTE, a frame (10ms) may be divided into 10 equally sized subframes. Each subframe mayinclude two consecutive time slots. A resource grid may be used torepresent the two time slots, each time slot including one or more timeconcurrent resource blocks (RBs) (also referred to as physical RBs(PRBs)). The resource grid is divided into multiple resource elements(REs). In LTE, for a normal cyclic prefix, an RB contains 12 consecutivesubcarriers in the frequency domain and 7 consecutive symbols (for DL,OFDM symbols; for UL, SC-FDMA symbols) in the time domain, for a totalof 84 REs. For an extended cyclic prefix, an RB contains 12 consecutivesubcarriers in the frequency domain and 6 consecutive symbols in thetime domain, for a total of 72 REs. The number of bits carried by eachRE depends on the modulation scheme.

As illustrated in FIG. 2A, some of the REs carry DL reference (pilot)signals (DL-RS) for channel estimation at the UE. The DL-RS may includecell-specific reference signals (CRS) (also sometimes called common RS),UE-specific reference signals (UE-RS), and channel state informationreference signals (CSI-RS). FIG. 2A illustrates CRS for antenna ports 0,1, 2, and 3 (indicated as R₀, R₁, R₂, and R₃, respectively), UE-RS forantenna port 5 (indicated as R₅), and CSI-RS for antenna port 15(indicated as R). FIG. 2B illustrates an example of various channelswithin a DL subframe of a frame. The physical control format indicatorchannel (PCFICH) is within symbol 0 of slot 0, and carries a controlformat indicator (CFI) that indicates whether the physical downlinkcontrol channel (PDCCH) occupies 1, 2, or 3 symbols (FIG. 2B illustratesa PDCCH that occupies 3 symbols). The PDCCH carries downlink controlinformation (DCI) within one or more control channel elements (CCEs),each CCE including nine RE groups (REGs), each REG including fourconsecutive REs in an OFDM symbol. A UE may be configured with aUE-specific enhanced PDCCH (ePDCCH) that also carries DCI. The ePDCCHmay have 2, 4, or 8 RB pairs (FIG. 2B shows two RB pairs, each subsetincluding one RB pair). The physical hybrid automatic repeat request(ARQ) (HARQ) indicator channel (PHICH) is also within symbol 0 of slot 0and carries the HARQ indicator (HI) that indicates HARQ acknowledgement(ACK)/negative ACK (NACK) feedback based on the physical uplink sharedchannel (PUSCH). The primary synchronization channel (PSCH) is withinsymbol 6 of slot 0 within subframes 0 and 5 of a frame, and carries aprimary synchronization signal (PSS) that is used by a UE to determinesubframe timing and a physical layer identity. The secondarysynchronization channel (SSCH) is within symbol 5 of slot 0 withinsubframes 0 and 5 of a frame, and carries a secondary synchronizationsignal (SSS) that is used by a UE to determine a physical layer cellidentity group number. Based on the physical layer identity and thephysical layer cell identity group number, the UE can determine aphysical cell identifier (PCI). Based on the PCI, the UE can determinethe locations of the aforementioned DL-RS. The physical broadcastchannel (PBCH) is within symbols 0, 1, 2, 3 of slot 1 of subframe 0 of aframe, and carries a master information block (MIB). The MIB provides anumber of RBs in the DL system bandwidth, a PHICH configuration, and asystem frame number (SFN). The physical downlink shared channel (PDSCH)carries user data, broadcast system information not transmitted throughthe PBCH such as system information blocks (SIBs), and paging messages.

As illustrated in FIG. 2C, some of the REs carry demodulation referencesignals (DM-RS) for channel estimation at the eNB. The UE mayadditionally transmit sounding reference signals (SRS) in the lastsymbol of a subframe. The SRS may have a comb structure, and a UE maytransmit SRS on one of the combs. The SRS may be used by an eNB forchannel quality estimation to enable frequency-dependent scheduling onthe UL. FIG. 2D illustrates an example of various channels within an ULsubframe of a frame. A physical random access channel (PRACH) may bewithin one or more subframes within a frame based on the PRACHconfiguration. The PRACH may include six consecutive RB pairs within asubframe. The PRACH allows the UE to perform initial system access andachieve UL synchronization. A physical uplink control channel (PUCCH)may be located on edges of the UL system bandwidth. The PUCCH carriesuplink control information (UCI), such as scheduling requests, a channelquality indicator (CQI), a precoding matrix indicator (PMI), a rankindicator (RI), and HARQ ACK/NACK feedback. The PUSCH carries data, andmay additionally be used to carry a buffer status report (BSR), a powerheadroom report (PHR), and/or UCI.

FIG. 3 is a block diagram of an eNB 310 in communication with a UE 350in an access network. In the DL, IP packets from the EPC 160 may beprovided to a controller/processor 375. The controller/processor 375implements layer 3 and layer 2 functionality. Layer 3 includes a radioresource control (RRC) layer, and layer 2 includes a packet dataconvergence protocol (PDCP) layer, a radio link control (RLC) layer, anda medium access control (MAC) layer. The controller/processor 375provides RRC layer functionality associated with broadcasting of systeminformation (e.g., MIB, SIBs), RRC connection control (e.g., RRCconnection paging, RRC connection establishment, RRC connectionmodification, and RRC connection release), inter radio access technology(RAT) mobility, and measurement configuration for UE measurementreporting; PDCP layer functionality associated with headercompression/decompression, security (ciphering, deciphering, integrityprotection, integrity verification), and handover support functions; RLClayer functionality associated with the transfer of upper layer packetdata units (PDUs), error correction through ARQ, concatenation,segmentation, and reassembly of RLC service data units (SDUs),re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; andMAC layer functionality associated with mapping between logical channelsand transport channels, multiplexing of MAC SDUs onto transport blocks(TBs), demuliplexing of MAC SDUs from TBs, scheduling informationreporting, error correction through HARQ, priority handling, and logicalchannel prioritization.

The transmit (TX) processor 316 and the receive (RX) processor 370implement layer 1 functionality associated with various signalprocessing functions. Layer 1, which includes a physical (PHY) layer,may include error detection on the transport channels, forward errorcorrection (FEC) coding/decoding of the transport channels,interleaving, rate matching, mapping onto physical channels,modulation/demodulation of physical channels, and MIMO antennaprocessing. The TX processor 316 handles mapping to signalconstellations based on various modulation schemes (e.g., binaryphase-shift keying (BPSK), quadrature phase-shift keying (QPSK),M-phase-shift keying (M-PSK), M-quadrature amplitude modulation(M-QAM)). The coded and modulated symbols may then be split intoparallel streams. Each stream may then be mapped to an OFDM subcarrier,multiplexed with a reference signal (e.g., pilot) in the time and/orfrequency domain, and then combined together using an Inverse FastFourier Transform (IFFT) to produce a physical channel carrying a timedomain OFDM symbol stream. The OFDM stream is spatially precoded toproduce multiple spatial streams. Channel estimates from a channelestimator 374 may be used to determine the coding and modulation scheme,as well as for spatial processing. The channel estimate may be derivedfrom a reference signal and/or channel condition feedback transmitted bythe UE 350. Each spatial stream may then be provided to a differentantenna 320 via a separate transmitter 318TX. Each transmitter 318TX maymodulate an RF carrier with a respective spatial stream fortransmission.

At the UE 350, each receiver 354RX receives a signal through itsrespective antenna 352. Each receiver 354RX recovers informationmodulated onto an RF carrier and provides the information to the receive(RX) processor 356. The TX processor 368 and the RX processor 356implement layer 1 functionality associated with various signalprocessing functions. The RX processor 356 may perform spatialprocessing on the information to recover any spatial streams destinedfor the UE 350. If multiple spatial streams are destined for the UE 350,they may be combined by the RX processor 356 into a single OFDM symbolstream. The RX processor 356 then converts the OFDM symbol stream fromthe time-domain to the frequency domain using a Fast Fourier Transform(FFT). The frequency domain signal comprises a separate OFDM symbolstream for each subcarrier of the OFDM signal. The symbols on eachsubcarrier, and the reference signal, are recovered and demodulated bydetermining the most likely signal constellation points transmitted bythe eNB 310. These soft decisions may be based on channel estimatescomputed by the channel estimator 358. The soft decisions are thendecoded and deinterleaved to recover the data and control signals thatwere originally transmitted by the eNB 310 on the physical channel. Thedata and control signals are then provided to the controller/processor359, which implements layer 3 and layer 2 functionality.

The controller/processor 359 can be associated with a memory 360 thatstores program codes and data. The memory 360 may be referred to as acomputer-readable medium. In the UL, the controller/processor 359provides demultiplexing between transport and logical channels, packetreassembly, deciphering, header decompression, and control signalprocessing to recover IP packets from the EPC 160. Thecontroller/processor 359 is also responsible for error detection usingan ACK and/or NACK protocol to support HARQ operations.

Similar to the functionality described in connection with the DLtransmission by the eNB 310, the controller/processor 359 provides RRClayer functionality associated with system information (e.g., MIB, SIBs)acquisition, RRC connections, and measurement reporting; PDCP layerfunctionality associated with header compression/decompression, andsecurity (ciphering, deciphering, integrity protection, integrityverification); RLC layer functionality associated with the transfer ofupper layer PDUs, error correction through ARQ, concatenation,segmentation, and reassembly of RLC SDUs, re-segmentation of RLC dataPDUs, and reordering of RLC data PDUs; and MAC layer functionalityassociated with mapping between logical channels and transport channels,multiplexing of MAC SDUs onto TBs, demuliplexing of MAC SDUs from TBs,scheduling information reporting, error correction through HARQ,priority handling, and logical channel prioritization.

Channel estimates derived by a channel estimator 358 from a referencesignal or feedback transmitted by the eNB 310 may be used by the TXprocessor 368 to select the appropriate coding and modulation schemes,and to facilitate spatial processing. The spatial streams generated bythe TX processor 368 may be provided to different antenna 352 viaseparate transmitters 354TX. Each transmitter 354TX may modulate an RFcarrier with a respective spatial stream for transmission.

The UL transmission is processed at the eNB 310 in a manner similar tothat described in connection with the receiver function at the UE 350.Each receiver 318RX receives a signal through its respective antenna320. Each receiver 318RX recovers information modulated onto an RFcarrier and provides the information to a RX processor 370.

The controller/processor 375 can be associated with a memory 376 thatstores program codes and data. The memory 376 may be referred to as acomputer-readable medium. In the UL, the controller/processor 375provides demultiplexing between transport and logical channels, packetreassembly, deciphering, header decompression, control signal processingto recover IP packets from the UE 350. IP packets from thecontroller/processor 375 may be provided to the EPC 160. Thecontroller/processor 375 is also responsible for error detection usingan ACK and/or NACK protocol to support HARQ operations.

FIG. 4 is an example timeline diagram 400 illustrating channel stateinformation (CSI) measurement and reporting. The timeline diagram 400shows interactions involving a UE 410 and a base station 420 over time.

The UE 410 receives an uplink grant from the base station 420, at 452.The UE 410 may receive an uplink grant in a trigger subframe. The uplinkgrant may indicate that the UE 410 may perform an UL transmission. In anaspect, the uplink grant may indicate available resources for uplinkcommunication.

At 454, the UE 410 determines a reference subframe to measure CSI forreporting, and determines a reporting subframe to report the CSI. Thereference subframe may be a downlink subframe. For example, thereference subframe may be located at or later than the subframe wherethe uplink grant is received, and before the reporting subframe. Forexample, the UE may determine the reporting subframe based on a delaybetween reception of the uplink grant and an uplink transmission, wherethe delay is indicated in the uplink grant.

At 456, the UE 410 measures CSI based on a downlink communication fromthe base station 420. The UE 410 may measure the CSI based on receptionconditions of the downlink communication in the reference subframe.

At 458, the UE 410 reports the CSI to the base station 420. The UE 410may report the CSI in the reporting subframe.

The CSI measurement and reporting may be periodic or aperiodic. Toperform the periodic CSI measurement, the UE 410 may measure the CSIperiodically. The UE 410 may perform the aperiodic CSI measurement whenthe aperiodic CSI measurement is triggered by a CSI trigger (e.g., viaDCI) received at the UE 410.

For periodic CSI measurement and reporting in LAA, the UE may performthe CSI measurement by selecting a latest valid reference subframe amongseveral reference subframes to measure the CSI, and report the measuredCSI to a base station. The reference subframes may be DL subframes. Avalid reference subframe may be a downlink subframe where CSI may bemeasured based on reception conditions in the downlink subframe. Thelatest valid reference subframe may be a last reference subframe in timebefore a reporting subframe in which the CSI is reported. For channelestimation based on a CRS and/or CSI reference signal (CSI-RS) forperiodic CSI reporting, the latest valid reference subframe is used as areference subframe for CSI reporting. To determine that a subframe is avalid reference subframe, the UE may detect a CRS transmission in symbol0 of a subframe and determine that the subframe is a full subframe. Ifthe UE does not detect the CRS transmission in the subframe, the UE maydetermine that the base station has not transmitted a CRS to the UE inthe subframe, and thus the subframe is not a valid reference subframe.For CRS-based channel estimation, the subframe for channel estimation isa non-MBSFN subframe. For CSI-RS based channel estimation, the referencesubframe should have valid CSI-RS transmissions.

The UE may not perform averaging of channel estimates across differenttransmissions because power variation on the CRS/CSI-RS transmissionsmay be unknown. For interference estimation, the UE may not estimateinterference in subframes in which the base station does not transmit.Periodic CSI may be measured at a fixed reference subframe, where thetiming delay between an uplink grant and an uplink transmission isfixed, and a trigger for a grant should be received in a subframe thatcarries reference resources. For example, if an uplink grant is sent insubframe n-4, the reference resources will be in subframe n-4, and theUE may perform uplink transmission in subframe n (e.g., to report theCSI in subframe n).

For aperiodic CSI measurement in LAA, the reference subframe may befixed at subframe “n-4” if the CSI is transmitted in subframe “n” for aframe structure type 1 (FS1) based transmission, for example. In otherwords, the subframe in which the UL grant is received is a validreference subframe for CSI measurement. Similarly for TDD systems basedon frame structure type 2 (FS2), the reference subframe may be a fixedsubframe (determined based on the FS2 configuration) based on thesubframe in which CSI is to be transmitted.

When determining the reference subframe for aperiodic CSI in enhancedLAA (eLAA), the timing delay between the UL grant and the ULtransmission may be configurable from 0 to 15 subframes, so as toprovide flexibility in configuring a reference subframe for CSImeasurement. Further, multiple transmission time interval (multi-TTI)grants may be supported where the subframe in which CSI is transmittedis a function of the number of scheduled subframes in the grant.

For eLAA, a reference subframe may be updated based on signaling from abase station because there may be a long delay between the triggering ofCSI in the UL grant and the transmission of CSI. The updated referencesubframe may be different for channel and interference estimation. In afirst scenario, (e.g., due to specific channel and interferenceconditions) the base station may receive an aperiodic CSI report basedon a triggering subframe in which a UL grant is received by the UE. Inthe first scenario, the UE may receive a UL grant in a triggeringsubframe and report the CSI measured in the triggering subframe,treating the triggering subframe as a reference subframe. In a secondscenario, the base station may receive an aperiodic CSI report based onthe latest reference subframe used for UL transmission after thetriggering subframe in which a UL grant is received by the UE. Thus, inthe second scenario, the UE may receive a UL grant in a triggeringsubframe, determine a latest reference subframe after the triggeringsubframe, and report the CSI that is measured in the latest referencesubframe. In addition, for frame structure type 3 (FS3), because theDL-UL configurations are dynamic DL-UL configurations, triggeringaperiodic CSI in a subframe by the base station may be advantageous.Instead of being limited to the first scenario or the second scenario,flexibility to choose between the triggering subframe and the latestreference subframe as a reference subframe for which CSI to report isdesired. Thus, an approach to provide flexibility for the base stationto choose between the reference resources in the triggering subframe andthe reference resources in the latest reference subframe is desired.

In an aspect, the base station may configure the UE with an indicationof a type of reference subframe to be used for aperiodic CSI reportingvia semi-static RRC signaling and/or via dynamic indication in the DCI.When the UE receives an RRC signal or DCI that has an indication of atype of reference subframe for aperiodic CSI reporting, the UE maydetermine a reference subframe for which CSI is reported based on thetype of reference subframe.

In an aspect, in a first case corresponding to a first type of referencesubframe, the reference subframe for aperiodic CSI reporting is thetriggering subframe. Thus, in the first case, if the base stationindicates to the UE the first type of reference subframe, the UE usesthe reference resources in the triggering subframe to measure CSI. In asecond case corresponding to a second type of reference subframe, thereference subframe for aperiodic CSI reporting is a subframe locatedbefore the reporting subframe in which the CSI is transmitted. Forexample, in the second case, the reference subframe for aperiodic CSIreporting is a subframe located one or more subframes before thereporting subframe. Thus, in the second case, if the base stationindicates to the UE the second type of reference subframe, the UEdetermines the reference subframe based on the reporting subframe. Inone example, the UE may determine the reference subframe for CSImeasurement to be at least a predefined number of subframes before thereporting subframe. For example, in the second case, the referencesubframe for aperiodic CSI reporting may be located after the triggeringsubframe, and thus the CSI may be measured after the triggering subframeand before the reporting subframe.

In an aspect, when the UE receives an uplink grant in a triggeringsubframe, the uplink grant may include information about a reportingsubframe in which the CSI is transmitted. For example, the grant mayinclude information about a delay between the uplink grant and areporting subframe in which the CSI is transmitted. Thus, in such anaspect, when the UE receives the uplink grant in the triggeringsubframe, the UE may determine the reporting subframe based on the delayinformation included in the uplink grant.

FIGS. 5A and 5B are example diagrams illustrating CSI measurement in areference subframe and CSI reporting in a reporting subframe, accordingto an aspect of the disclosure. FIG. 5A is an example diagram 500illustrating the first case where the reference subframe is thetriggering subframe, according to an aspect of the disclosure. In theexample diagram 500 of FIG. 5A, the UE receives the UL grant in subframe(n-9). In FIG. 5A, because the UE received (e.g., via an RRC signal orDCI) an indication from the base station to use the first type ofreference subframe, the UE determines that the reference subframe forCSI measurement is the triggering subframe, which is subframe n-9. Thus,the UE may measure the CSI in subframe n-9. Subsequently, the UE reportsin the reporting subframe (subframe n) the CSI measured in subframe n-9.FIG. 5B is an example diagram 550 illustrating the second case where thereference subframe is determined based on the reporting subframe,according to an aspect of the disclosure. In the example diagram 550 ofFIG. 5B, the UE receives the UL grant in subframe n-9. Because the UEreceived (e.g., via an RRC signal or DCI) an indication from the basestation to use the second type of reference subframe, the UE determinesthat the reference subframe for CSI measurement may be at least 4subframes before the reporting subframe (subframe n). For example, theUE may select any valid reference subframe for CSI measurement that isat least 4 subframes before the reporting subframe and after thetriggering subframe. Thus, in the example of FIG. 5B, the UE may selectany one of valid reference subframes n-4, n-5, n-6, n-7, and n-8 as areference subframe for CSI measurement. As discussed above, a validreference subframe may be a downlink subframe where CSI may be measuredbased on reception conditions in the downlink subframe. In one aspect,the UE may select the latest valid reference subframe, which is subframen-4, as the reference subframe for CSI measurement. Hence, as shown inFIG. 5B, the UE may measure the CSI in subframe n-4. In an aspect, theUE may determine that a subframe is a valid reference subframe if the UEcan detect a CRS transmission in symbol 0 of the subframe and determinethat the subframe is a full subframe. After measuring the CSI insubframe n-4, the UE reports in the reporting subframe (subframe n) theCSI measured in subframe n-4.

In another aspect, the UE receives a UL grant that indicates that the UEmay perform UL transmission, but the UL grant may not includeinformation about a reporting subframe in which UL transmission isperformed. Thus, sometime after receiving the UL grant, the UE mayreceive a trigger signal indicating one or more reporting subframes inwhich UL transmission may be performed. For example, the trigger signalmay indicate a delay between the trigger signal and a reporting subframein which the CSI is transmitted. FIGS. 6A and 6B are example diagramsillustrating CSI measurement in a reference subframe and CSI reportingin a reporting subframe, according to another aspect of the disclosure.FIG. 6A is an example diagram 600 illustrating the first case where thereference subframe is the triggering subframe, according to anotheraspect of the disclosure. In the example diagram 600 of FIG. 6A, the UEreceives a UL grant in subframe p. Because the UE received an indicationfrom the base station to use the first type of reference subframe, theUE determines that the reference subframe for CSI measurement is thetriggering subframe, which is subframe p. Thus, the UE may measure theCSI in subframe p. Sometime after receiving the UL grant, the UEreceives a trigger signal (e.g., in subframe n-6) indicating that areporting subframe in which the CSI measurement is to be transmitted issubframe n (e.g., indicating a 6 subframe delay from the triggersignal). The UE reports in the reporting subframe (subframe n) the CSImeasured in subframe p. FIG. 6B is an example diagram 650 illustratingthe second case where the reference subframe is determined based on thereporting subframe, according to another aspect of the disclosure. Inthe example diagram 650 of FIG. 6B, the UE receives the UL grant insubframe p. Because the UE received an indication from the base stationto use the second type of reference subframe, the UE determines that thereference subframe for CSI measurement may be at least 4 subframesbefore the reporting subframe. For example, the UE may select any validreference subframe for CSI measurement that is at least 4 subframesbefore the reporting subframe and after the triggering subframe.Sometime after receiving the UL grant, the UE receives a trigger signal(e.g., in subframe n-6) indicating that a reporting subframe in whichthe CSI measurement is to be transmitted is subframe n (e.g., indicatinga 6 subframe delay from the trigger signal). Subsequently, because thereference subframe for CSI measurement may be at least 4 subframesbefore the reporting subframe, the UE may select any one of validreference subframes n-4 and n-5 as a reference subframe for CSImeasurement. The UE may select the latest valid reference subframe,which is subframe n-4, as the reference subframe for CSI measurement.Hence, as shown in FIG. 6B, the UE may measure the CSI in subframe n-4.The UE reports in the reporting subframe (subframe n) the CSI measuredin subframe n-4.

In an aspect, for multi-TTI grants triggering aperiodic CSI based on thesubframe in which CSI is transmitted, the UE may determine a referencesubframe for CSI measurement based on the reporting subframe in whichthe CSI is reported. The multi-TTI grants may be dynamically indicatedin a DCI. At least one of the multi-TTI grants may indicate thereporting subframe. FIG. 7 is an example diagram 700 illustrating CSImeasurement and reporting based on multi-TTI grants. The UE receives themulti-TTI grants in subframes n-7, n-8, n-9. Because the UE receivedmulti-TTI grants, the UE determines that the reference subframe for CSImeasurement is based on the reporting subframe, and may be at least 4subframes before the reporting subframe (subframe n). Thus, the UE mayselect any one of valid reference subframes n-4, n-5, and n-6 as areference subframe for CSI measurement. The UE may select the latestvalid reference subframe, which is subframe n-4, as the referencesubframe for CSI measurement. Hence, as shown in FIG. 7, the UE maymeasure the CSI in subframe n-4. The UE reports in the reportingsubframe (subframe n) the CSI measured in subframe n-4.

In an aspect, collision between periodic CSI measurement/reporting andaperiodic

CSI measurement/reporting may also be considered. The UE may not beconfigured to transmit HARQ ACK or NACK of the licensed carriers on theunlicensed carriers. Thus, configuration of simultaneous transmission ofa PUCCH on a the licensed carrier and a PUSCH on an unlicensed carriermay be supported for eLAA. In this scenario, the UE may transmitperiodic CSI on the licensed carrier and aperiodic CSI on the unlicensedcarrier. For example, the UE may transmit periodic CSI and/or HARQACK/NACK on a PUCCH (e.g. on a primary cell in a licensed spectrum), andmay transmit aperiodic CSI and/or HARQ ACK/NACK on a PUSCH (e.g., on asecondary cell in an unlicensed spectrum). Assuming both the PUCCH andthe PUSCH are on the licensed carriers, since simultaneous transmissionof the PUCCH and the PUSCH may not be desirable on the licensedcarriers, the periodic CSI that was to be carried via the PUCCH may betransmitted via the PUSCH on the licensed carrier using UCI piggybackingand the PUCCH with the periodic CSI may be dropped.

However, when aperiodic CSI is to be transmitted via a PUSCH on theunlicensed carrier, the HARQ ACK/NACK on the licensed carrier may have ahigh priority and may not be transmitted on the unlicensed carrier. Inother words, HARQ ACK/NACK on the licensed carrier may not be carried onthe unlicensed carrier while the CSI may still be carried on theunlicensed carrier. Various aspects may address such a scenario.

In an aspect, for HARQ ACK/NACK reporting in eLAA when the UE isconfigured for carrier aggregation (CA), a HARQ ACK/NACK cell group maybe defined with at least one licensed carrier (e.g., in a primary cell)carrying a PUCCH and with one or more unlicensed carriers (e.g., in asecondary cell). The HARQ ACK/NACK of all the serving cells in the HARQACK/NACK cell group may be reported on the licensed carrier either onthe PUCCH or on the PUSCH. With such a configuration, the HARQ ACK/NACKof the licensed carriers may not be transmitted on the unlicensedcarrier. If a PUSCH is scheduled on an unlicensed carrier, the UE maysimultaneously transmit a PUCCH and/or a PUSCH on the licensed carrierand a PUSCH on the unlicensed carrier.

In an aspect, for HARQ ACK/NACK reporting and/or periodic CSI reportingin eLAA, the UE may define the HARQ ACK/NACK cell group where the HARQACK/NACK and/or periodic CSI are reported only on the licensed carriersprovided by the HARQ ACK/NACK cell group. The HARQ ACK/NACK and/or theperiodic CSI may be reported on the licensed carrier either on the PUCCHor on the PUSCH. Thus, the HARQ ACK/NACK and/or the periodic CSI reportfor serving cells in a HARQ ACK/NACK cell group may be carried on thelicensed carrier and may not be carried on the unlicensed carrier, whichis consistent with eLAA that may not allow a PUCCH on the unlicensedcarrier.

In an aspect, for aperiodic CSI reporting in eLAA, the UE may define acell group for licensed carriers (e.g., in the primary cell) and a cellgroup for unlicensed carriers (e.g., in the secondary cell), and thusmay utilize a dual connectivity framework that allows the UE to connectto two different cell groups (e.g., the primary cell and the secondarycell). In particular, the aperiodic CSI reporting on the unlicensedcarriers may be self-contained within the unlicensed carriers and may beindependent of periodic and aperiodic CSI reporting on the licensedcarriers. Thus, if the UE receives a trigger signal via a carrier in thecell group for licensed carriers, the aperiodic CSI reporting on thelicensed carrier may be triggered (e.g., via a UL grant) on the licensedcarrier, and may not be triggered on the unlicensed carrier. On theother hand, if the UE receives a trigger signal via a carrier in thecell group for unlicensed carriers, the aperiodic CSI reporting on theunlicensed carrier is triggered at the UE (e.g., via a UL grant) on theunlicensed carrier and cannot be triggered on the licensed carrier. TheUE may simultaneously transmit periodic CSI on the licensed carrier andaperiodic CSI on the unlicensed carrier. Alternatively, the UE maysimultaneously transmit periodic CSI and aperiodic CSI on the sameunlicensed carrier. In an aspect, one aperiodic CSI cell group includingunlicensed carriers may be defined for a UE configured for CA.

In another aspect, the triggering of aperiodic CSI from the unlicensedcarriers under the CA framework in a CA configuration may be prevented.If a number of CSI computations exceeds a limit imposed by a UEcapability constraint for simultaneously handling several CSImeasurement/reporting processes, the UE may drop the aperiodic CSI onthe unlicensed carrier.

A UE configured for CA may have a maximum transmit power constraint suchthat the UE may need to use a power scaling procedure to allocatetransmit power to the configured carriers up to the maximum transmitpower constraint. The UE may allocate transmit power to the configuredcarriers considering the CSI reporting procedure discussed above. The UEmay consider different priorities for different carriers and/ordifferent channels when allocating transmit power to the carriers (e.g.,for transmitting an uplink channel such as a PUSCH or a PUSCH). Forexample, an uplink channel carrying HARQ ACK/NACK and/or CSI may have ahigher priority than a channel that is not carrying the HARQ ACK/NACKand/or the CSI. Further, different priorities may be assigned fordifferent types of transmissions (e.g., licensed carrier transmission v.unlicensed carrier transmission).

In an aspect, the UE may prioritize a licensed carrier carrying anuplink channel (e.g., PUCCH or a PUSCH) with UCI above other carriers,and thus first allocates the UE's transmit power to a licensed carriercarrying an uplink channel (e.g., PUCCH or a PUSCH) with UCI. Afterallocating the UE's transmit power to the licensed carrier carrying theuplink channel with the UCI, if there is any remaining transmit power atthe UE, an unlicensed carrier with a aperiodic CSI transmission may beprioritized next, and thus the UE allocates the remaining transmit poweror a portion of the remaining power to the unlicensed carrier with theaperiodic CSI transmission. After allocating the UE's transmit power toa licensed carrier carrying the uplink channel with the UCI and to anunlicensed carrier with the aperiodic CSI transmission, if the UE stillhas remaining transmit power, the remaining transmit power or a portionof the remaining transmit power may be shared among a subset of carriersincluding remaining licensed and unlicensed carriers equally if thecarriers are allocated non-zero power. In particular, the UE may equallyor unequally allocate up to the rest of the remaining power tocommunication on the licensed carriers and communication on theunlicensed carriers. Each transmit power allocation may be an allocationof a minimum transmit power for the UE to successfully transmit ULcommunication to the corresponding serving base station (e.g., to allowthe serving base station to successfully receive the UL communication).

FIG. 8 is a flowchart 800 of a method of wireless communication,according to an aspect of the disclosure. The method may be performed bya UE (e.g., the UE 410, the apparatus 1202/1202′). The flowchart 800describes approaches to select a reference subframe to measure CSI inthe reference subframe, and to report the measured CSI. The flowchart800 further describes approaches to determine a reporting subframe wherethe measured CSI is transmitted.

At 802, the UE receives a grant for uplink communication. For example,as discussed supra, the UE may receive an uplink grant from a basestation in a triggering subframe. For example, as discussed supra, thetriggering subframe may be a downlink subframe. For example, asillustrated in FIGS. 5A and 5B, the UE may receive a UL grant insubframe n-9. For example, as discussed supra, the uplink grant mayindicate that the UE may perform UL transmission.

At 804, the UE determines a reporting subframe based on the grant. Forexample, as discussed supra, the UE may select, based on the uplinkgrant, a reporting subframe in which the CSI is to be transmitted. Forexample, as discussed supra, the uplink grant may indicate availableresources (e.g., available UL subframes) for uplink communication, andthus the UE may select the reporting subframe based on the availableresources indicated in the uplink grant.

In an aspect, the grant indicates a delay between reception of the grantand an uplink transmission, and the reporting subframe is determinedbased on the delay. For example, as discussed supra, in an aspect, theuplink grant may include information about a delay between the uplinkgrant and a reporting subframe in which the CSI is transmitted. Thus, asdiscussed supra, when the UE receives the uplink grant, the UE maydetermine the reporting subframe based on the delay information includedin the uplink grant.

In another aspect, at 803, the UE may receive a trigger signalindicating a location of the reporting subframe, where the UE maydetermine the reporting subframe based on the grant and the triggersignal. For example, as discussed supra, in an aspect, sometime afterreceiving the UL grant, the UE may receive a trigger signal indicatingone or more reporting subframes in which UL transmission may beperformed. For example, as discussed supra, the trigger signal mayindicate a delay between the trigger signal and a reporting subframe.For example, as illustrated in FIGS. 6A and 6B, after receiving anuplink grant in subframe p, the UE may receive a trigger signal insubframe n-6, indicating that a reporting subframe in which the CSImeasurement is to be transmitted is subframe n.

At 806, the UE determines whether to select, as a reference subframe, atriggering subframe in which the grant is received or a subframe beforethe reporting subframe. For example, as discussed supra, the basestation may indicate to the UE either a first type of reference subframeor a second type of reference frame. For example, as discussed supra, ifthe base station indicates to the UE the first type of referencesubframe, the UE uses the reference resources in the triggering subframeto measure CSI (e.g., as illustrated in FIG. 5A). For example, asdiscussed supra, if the base station indicates to the UE the second typeof reference subframe, the UE determines the reference subframe based onthe reporting subframe, where the reference subframe is located beforethe reporting subframe (e.g., as illustrated in FIG. 5B).

In an aspect, the UE may determine whether to select the triggeringsubframe or the subframe before the reporting subframe based on a RRCsignal or a dynamic indication in DCI. For example, as discussed supra,the base station may configure the UE with an indication of a type ofreference subframe to be used for aperiodic CSI reporting viasemi-static RRC signaling and/or via dynamic indication in the DCI.

At 808, the UE may measure CSI in the reference subframe. For example,as discussed supra, the UE measures the CSI in the reference subframe.For example, as illustrated in FIG. 5A, the UE may measure the CSI inthe reference subframe (subframe n-9). For example, as illustrated inFIG. 5B, the UE may measure the CSI in the reference subframe (subframen-4).

At 810, the UE transmits, in the reporting subframe, the CSI measured inthe reference subframe. For example, as discussed supra, the UEtransmits the CSI measurement in the reporting subframe. For example, asillustrated in FIGS. 5A and 5B, the UE transmits, in the reportingsubframe (subframe n), the CSI measured in the reference subframe.

In an aspect, the subframe before the reporting subframe may be locatedafter the triggering subframe. For example, as discussed supra, in thesecond case where the reference subframe is located in a subframe beforethe reporting subframe, the reference subframe for aperiodic CSIreporting may be located after the triggering subframe. For example, asillustrated in FIG. 5B, the reference subframe for CSI measurement issubframe n-4 that is located after the triggering subframe (subframen-9) and before the reporting subframe (subframe n). In such an aspect,the subframe before the reporting subframe may be located at least apredefined number of subframes before the reporting subframe. Forexample, as discussed supra, the UE may determine the reference subframefor CSI measurement to be at least a predefined number of subframesbefore the reporting subframe. For example, as illustrated in FIG. 5B,the UE may determine that the reference subframe for CSI measurement maybe at least 4 subframes before the reporting subframe (subframe n), andthus may select subframe n-4 as the reference subframe.

In an aspect, the grant may include one or more multi-TTI grantsdynamically indicated in a DCI. For example, as discussed supra, themulti-TTI grants may be dynamically indicated in a DCI, and at least oneof the multi-TTI grants may indicate a reporting subframe. In such anaspect, the reporting subframe may be one of subframes indicated by oneor more multi-TTI grants. For example, as discussed supra, at least oneof the multi-TTI grants may include a grant indicating the reportingsubframe in which the CSI is reported. In such an aspect, the subframebefore the reporting subframe may be selected as the reference subframebased on the one or more multi-TTI grants. For example, as discussedsupra in reference to FIG. 7, because the UE received multi-TTI grants,the UE determines that the reference subframe for CSI measurement isbased on the reporting subframe, and may be at least 4 subframes beforethe reporting subframe (subframe n).

FIG. 9 is a flowchart 900 of a method of wireless communication,according to an aspect of the disclosure. The method may be performed bya UE (e.g., the UE 410, the apparatus 1202/1202′). The flowchart 900describes approaches to utilize a licensed carrier to report a HARQACK/NACK or periodic CSI, so as to be consistent with eLAA that may notallow a PUCCH on the unlicensed carrier. For example, the flowchart 900describes approaches to define a HARQ ACK/NACK cell group with at leastone licensed carrier carrying a PUCCH and with one or more unlicensedcarriers, such that a HARQ ACK/NACK and/or a periodic CSI report forserving cells in the HARQ ACK/NACK cell group may be reported on thelicensed carrier.

At 902, the UE determines a cell group, the cell group including atleast one licensed carrier configured with an uplink control channel andone or more unlicensed carriers. For example, as discussed supra, a HARQACK/NACK cell group may be defined with at least one licensed carrier(e.g., in a primary cell) carrying a PUCCH and with one or moreunlicensed carriers (e.g., in a secondary cell).

At 904, the UE reports at least one of a HARQ ACK/NACK or periodic CSIfor the cell group on the at least one licensed carrier provided by thecell group. For example, as discussed supra, the UE may define the HARQACK/NACK cell group where the HARQ ACK/NACK and/or periodic CSI arereported only on the licensed carriers provided by the HARQ ACK/NACKcell group.

In an aspect, the at least one of the HARQ ACK/NACK or the periodic CSIare reported via the uplink control channel or an uplink shared channel.For example, as discussed supra, the HARQ ACK/NACK and/or the periodicCSI may be reported on the licensed carrier either on the PUCCH or onthe PUSCH.

FIG. 10 is a flowchart 1000 of a method of wireless communication,according to an aspect of the disclosure. The method may be performed bya UE (e.g., the UE 410, the apparatus 1202/1202′). The flowchart 1000describes approaches to define a cell group for licensed carriers (e.g.,in the primary cell) and a cell group for unlicensed carriers (e.g., inthe secondary cell). The flowchart 1000 describes approaches to performthe aperiodic CSI reporting on the licensed carrier and not on theunlicensed carrier if the UE receives a trigger signal via a carrier inthe cell group for licensed carriers. The flowchart 1000 describesapproaches to perform the aperiodic CSI reporting on the unlicensedcarrier and not on the licensed carrier if the UE receives a triggersignal via a carrier in the cell group for unlicensed carriers.

At 1002, the UE determines a first cell group including one or morelicensed carriers.

For example, as discussed supra, the UE may define a first cell groupfor licensed carriers.

At 1004, the UE determines a second cell group including one of moreunlicensed carriers. For example, as discussed supra, the UE may definea second cell group for unlicensed carriers. For example, as discussedsupra, for aperiodic CSI reporting in eLAA, the UE may define a firstcell group for licensed carriers (e.g., in the primary cell) and a cellgroup for unlicensed carriers (e.g., in the secondary cell). Thus, theUE may utilize a dual connectivity framework.

At 1006, the UE receives a CSI trigger. For example, as discussed supra,the aperiodic CSI reporting at the UE may be triggered (e.g., via a ULgrant from a base station). For example, as discussed supra, the CSItrigger may be received on a licensed carrier or on an unlicensedcarrier.

At 1008, the UE determines whether the CSI trigger was received on acarrier in the first cell group or on a carrier in the second cellgroup. For example, as discussed supra, the UE may determine whether theUE receives a trigger signal via a carrier in the cell group forlicensed carriers or via a carrier in the cell group for unlicensedcarriers.

If the CSI trigger was received on a first carrier in the first cellgroup, at 1010, the UE transmits the CSI on a licensed carrier in thefirst cell group, and, at 1012, may refrain from transmitting the CSI onan unlicensed carrier in the second cell group. In an aspect, if the CSItrigger was received on the first carrier in the first cell group, theUE may transmit the CSI only on the licensed carrier in the first cellgroup. For example, as discussed supra, if the UE receives a triggersignal via a carrier in the cell group for licensed carriers, theaperiodic CSI reporting on the licensed carrier may be triggered (e.g.,via a UL grant) on the licensed carrier, and may not be triggered on theunlicensed carrier.

If the CSI trigger was received on a second carrier in the second cellgroup, at 1014, the UE transmits the CSI on an unlicensed carrier in thesecond cell group, and at 1016, the UE may refrain from transmitting theCSI on a licensed carrier in the first cell group. In an aspect, if theCSI trigger was received on the second carrier in the first secondgroup, the UE may transmit the CSI only on the unlicensed carrier in thesecond cell group. For example, as discussed supra, if the UE receives atrigger signal via a carrier in the cell group for unlicensed carriers,the aperiodic CSI reporting on the unlicensed carrier is triggered(e.g., via a UL grant) on the unlicensed carrier and cannot be triggeredon the licensed carrier.

In an aspect, the second cell group for reporting aperiodic CSI on anunlicensed carrier in the second cell group may be a single group ofcells. For example, as discussed supra, one aperiodic CSI cell groupincluding unlicensed carriers may be defined for a UE configured for CA.

FIG. 11 is a flowchart 1100 of a method of wireless communication,according to an aspect of the disclosure. The method may be performed bya UE (e.g., the UE 410, the apparatus 1202/1202′). The UE configured forCA may have a maximum transmit power constraint. Thus, the flowchart1100 describes approaches to allocate transmit power to the configuredcarriers up to the maximum transmit power constraint (e.g., based ondifferent priorities for different carriers and/or different channels).

At 1102, the UE allocates a first portion of a total transmit power totransmission of an uplink control information to a licensed serving cellvia an uplink channel on a licensed carrier. In an aspect, the uplinkchannel includes at least one of a PUCCH or a PUSCH. For example, asdiscussed supra, the UE may prioritize a licensed carrier carrying anuplink channel (e.g., PUCCH or a PUSCH) with UCI above other carriers,and thus first allocates the UE's transmit power to a licensed carriercarrying an uplink channel (e.g., PUCCH or a PUSCH) with UCI.

At 1104, the UE allocates a second portion of the total transmit powerto transmission of an aperiodic CSI on an unlicensed carrier to anunlicensed cell, where the second portion is less than or equal toremaining portion of the total transmit power after allocating the firstportion to the uplink channel. For example, as discussed supra, afterallocating the UE's transmit power to the licensed carrier carrying theuplink channel with the UCI, if there is any remaining transmit power atthe UE, an unlicensed carrier with a aperiodic CSI transmission may beprioritized next, and thus the UE allocates the remaining transmit poweror a portion of the remaining transmit power to the unlicensed carrierwith the aperiodic CSI transmission.

At 1106, the UE allocates a third portion of the total transmit power toa first communication via the licensed carrier and a secondcommunication via the unlicensed carrier, where the third portion isless than or equal to remaining portion of the total transmit powerafter the allocation of the first portion and the second portion. Forexample, as discussed supra, after allocating the UE's transmit power toa licensed carrier carrying the uplink channel with the UCI and to anunlicensed carrier with the aperiodic CSI transmission, if the UE stillhas remaining transmit power, up to the remaining transmit power may beshared among a subset of carriers including remaining licensed andunlicensed carriers equally if the carriers are allocated non-zeropower.

In an aspect, the third portion is allocated equally to the firstcommunication via the licensed carrier and the second communication viathe unlicensed carrier. For example, as discussed supra, the UE mayequally or unequally allocate the rest of the remaining power tocommunication on the licensed carriers and communication on theunlicensed carriers

FIG. 12 is a conceptual data flow diagram 1200 illustrating the dataflow between different means/components in an exemplary apparatus 1202.The apparatus may be a UE. The apparatus includes a reception component1204, a transmission component 1206, a subframe determination component1208, a CSI/Feedback management component 1210, a cell group managementcomponent 1212, and a transmit power management component 1214.

According to an aspect of the disclosure, the subframe determinationcomponent 1208 receives a grant for uplink communication (e.g., from abase station 1230), via the reception component 1204, at 1252 and 1254.The subframe determination component 1208 determines a reportingsubframe based on the grant. In an aspect, the grant may indicate adelay between reception of the grant and an uplink transmission, and thereporting subframe may be determined based on the delay. In anotheraspect, the subframe determination component 1208 may receive a triggersignal indicating a location of the reporting subframe), via thereception component 1204, at 1252 and 1254, where the subframedetermination component 1208 may determine the reporting subframe basedon the grant and the trigger signal.

The subframe determination component 1208 determines whether to select,as a reference subframe, a triggering subframe in which the grant isreceived or a subframe before the reporting subframe. In an aspect, thesubframe determination component 1208 may determine whether to selectthe triggering subframe or the subframe before the reporting subframebased on a RRC signal or a dynamic indication in DCI. The subframedetermination component 1208 may forward information about the referencesubframe to the CSI/Feedback management component 1210, at 1256. TheCSI/Feedback management component 1210 may measure CSI in the referencesubframe. The CSI/Feedback management component 1210 transmits, in thereporting subframe, CSI/Feedback measured in the reference subframe(e.g., to the base station 1230), via the transmission component 1206,at 1258 and 1260.

In an aspect, the subframe before the reporting subframe is locatedafter the triggering subframe. In such an aspect, the subframe beforethe reporting subframe is located at least a predefined number ofsubframes before the reporting subframe.

In an aspect, the grant includes one or more multi-TTI grantsdynamically indicated in a DCI. In such an aspect, the reportingsubframe is one of subframes indicated by one or more multi-TTI grants.In such an aspect, the subframe before the reporting subframe isselected as the reference subframe based on the one or more multi-TTIgrants.

According to another aspect of the disclosure, the cell group managementcomponent 1212 determines a cell group, the cell group including atleast one licensed carrier configured with an uplink control channel andone or more unlicensed carriers (e.g., based on information receivedfrom the base station 1230 at 1252 and 1262). The cell group managementcomponent 1212 may forward information about the cell group to theCSI/Feedback management component 1210, at 1264. The CSI/Feedbackmanagement component 1210 reports at least one of a HARQ ACK/NACK orperiodic CSI for the cell group on the at least one licensed carrierprovided by the cell group (e.g., to the base station 1230), via thetransmission component 1206, at 1258 and 1260. In an aspect, the atleast one of the HARQ ACK/NACK or the periodic CSI are reported via theuplink control channel or an uplink shared channel.

According to another aspect of the disclosure, the cell group managementcomponent 1212 determines a first cell group including one or morelicensed carriers. The cell group management component 1212 determines asecond cell group including one of more unlicensed carriers. The cellgroup management component 1212 may forward information about the firstcell group and the cell group to the CSI/Feedback management component1210, at 1264. The CSI/Feedback management component 1210 receives a CSItrigger (e.g., from the base station 1230), via the reception component1204, at 1252 and 1266. The CSI/Feedback management component 1210determines whether the CSI trigger was received on a carrier in thefirst cell group or on a carrier in the second cell group. If the CSItrigger was received on a first carrier in the first cell group, theCSI/Feedback management component 1210 transmits (e.g., to the basestation 1230) the CSI on a licensed carrier in the first cell group, viathe transmission component 1206, at 1258 and 1260, and may refrain fromtransmitting the CSI on an unlicensed carrier in the second cell group.In an aspect, if the CSI trigger was received on the first carrier inthe first cell group, the CSI/Feedback management component 1210 maytransmit the CSI only on the licensed carrier in the first cell group,via the transmission component 1206, at 1258 and 1260. If the CSItrigger was received on a second carrier in the second cell group, theCSI/Feedback management component 1210 transmits (e.g., to the basestation 1230) the CSI on an unlicensed carrier in the second cell group,via the transmission component 1206, at 1258 and 1260, and may refrainfrom transmitting the CSI on the licensed carrier in the first cellgroup. In an aspect, if the CSI trigger was received on the secondcarrier in the first second group, the CSI/Feedback management component1210 may transmit the CSI only on the unlicensed carrier in the secondcell group, via the transmission component 1206, at 1258 and 1260. In anaspect, the second cell group for reporting aperiodic CSI on anunlicensed carrier in the second cell group may be a single group ofcells.

According to another aspect of the disclosure, the transmit powermanagement component 1214 allocates a first portion of a total transmitpower to transmission of an UCI to a licensed serving cell via an uplinkchannel on a licensed carrier. In an aspect, the uplink channel mayinclude at least one of a PUCCH or a PUSCH. The transmit powermanagement component 1214 allocates a second portion of the totaltransmit power to transmission of an aperiodic CSI on an unlicensedcarrier to an unlicensed cell, where the second portion is less than orequal to remaining portion of the total transmit power after allocatingthe first portion to the uplink channel. The transmit power managementcomponent 1214 allocates a third portion of the total transmit power toa first communication via the licensed carrier and a secondcommunication via the unlicensed carrier, where the third portion isless than or equal to remaining portion of the total transmit powerafter the allocation of the first portion and the second portion. In anaspect, the third portion is allocated equally to the firstcommunication via the licensed carrier and the second communication viathe unlicensed carrier. The transmit power management component 1214 mayforward the information about the transmit power allocation to thetransmission component 1206, at 1266, such that the transmissioncomponent 1206 may perform transmission based on the transmit powerallocation.

The apparatus may include additional components that perform each of theblocks of the algorithm in the aforementioned flowcharts of FIGS. 8-11.As such, each block in the aforementioned flowcharts of FIGS. 8-11 maybe performed by a component and the apparatus may include one or more ofthose components. The components may be one or more hardware componentsspecifically configured to carry out the stated processes/algorithm,implemented by a processor configured to perform the statedprocesses/algorithm, stored within a computer-readable medium forimplementation by a processor, or some combination thereof.

FIG. 13 is a diagram 1300 illustrating an example of a hardwareimplementation for an apparatus 1202′ employing a processing system1314. The processing system 1314 may be implemented with a busarchitecture, represented generally by the bus 1324. The bus 1324 mayinclude any number of interconnecting buses and bridges depending on thespecific application of the processing system 1314 and the overalldesign constraints. The bus 1324 links together various circuitsincluding one or more processors and/or hardware components, representedby the processor 1304, the components 1204, 1206, 1208, 1210, 1212,1214, and the computer-readable medium/memory 1306. The bus 1324 mayalso link various other circuits such as timing sources, peripherals,voltage regulators, and power management circuits, which are well knownin the art, and therefore, will not be described any further.

The processing system 1314 may be coupled to a transceiver 1310. Thetransceiver 1310 is coupled to one or more antennas 1320. Thetransceiver 1310 provides a means for communicating with various otherapparatus over a transmission medium. The transceiver 1310 receives asignal from the one or more antennas 1320, extracts information from thereceived signal, and provides the extracted information to theprocessing system 1314, specifically the reception component 1204. Inaddition, the transceiver 1310 receives information from the processingsystem 1314, specifically the transmission component 1206, and based onthe received information, generates a signal to be applied to the one ormore antennas 1320. The processing system 1314 includes a processor 1304coupled to a computer-readable medium/memory 1306. The processor 1304 isresponsible for general processing, including the execution of softwarestored on the computer-readable medium/memory 1306. The software, whenexecuted by the processor 1304, causes the processing system 1314 toperform the various functions described supra for any particularapparatus. The computer-readable medium/memory 1306 may also be used forstoring data that is manipulated by the processor 1304 when executingsoftware. The processing system 1314 further includes at least one ofthe components 1204, 1206, 1208, 1210, 1212, 1214. The components may besoftware components running in the processor 1304, resident/stored inthe computer readable medium/memory 1306, one or more hardwarecomponents coupled to the processor 1304, or some combination thereof.The processing system 1314 may be a component of the UE 350 and mayinclude the memory 360 and/or at least one of the TX processor 368, theRX processor 356, and the controller/processor 359.

In one configuration, the apparatus 1202/1202′ for wirelesscommunication includes means for receiving a grant for uplinkcommunication, means for determining a reporting subframe based on thegrant, means for determining whether to select, as a reference subframe,a triggering subframe in which the grant is received or a subframebefore the reporting subframe, and means for transmitting, in thereporting subframe, CSI measured in the reference subframe. In anaspect, the apparatus 1202/1202′ may further include means for receivinga trigger signal indicating a location of the reporting subframe, wherethe means for determining the reporting subframe is configured todetermine the reporting subframe based on the grant and the triggersignal. In an aspect, the means for determining whether to select thetriggering subframe or the subframe before the reporting subframe isconfigured to determine whether to select the triggering subframe or thesubframe before the reporting subframe based on an RRC signal or adynamic indication in downlink control information.

In another configuration, the apparatus 1202/1202′ for wirelesscommunication includes means for determining a cell group, the cellgroup including at least one licensed carrier configured with an uplinkcontrol channel and one or more unlicensed carriers, and means forreporting at least one of a hybrid automatic repeat request (HARQ)acknowledgement/negative-acknowledgement (ACK/NACK) or periodic channelstate information (CSI) for the cell group on the at least one licensedcarrier provided by the cell group.

In another configuration, the apparatus 1202/1202′ for wirelesscommunication includes means for determining a first cell groupincluding one or more licensed carriers, means for determining a secondcell group including one of more unlicensed carriers, means forreceiving a CSI trigger, means for transmitting the CSI on a licensedcarrier in the first cell group if the CSI trigger was received on afirst carrier in the first cell group, and means for transmitting theCSI on an unlicensed carrier in the second cell group if the CSI triggerwas received on a second carrier in the second cell group. In an aspect,the apparatus 1202/1202′ may further include means for refraining fromtransmitting the CSI on a licensed carrier in the first cell group ifthe CSI trigger was received on the second carrier in the second cellgroup, and means for refraining from transmitting the CSI on anunlicensed carrier in the second cell group if the C SI trigger wasreceived on the first carrier in the first cell group.

In another configuration, the apparatus 1202/1202′ for wirelesscommunication includes means for allocating a first portion of a totaltransmit power to transmission of an uplink control information to alicensed serving cell via an uplink channel on a licensed carrier, andmeans for allocating a second portion of the total transmit power totransmission of an aperiodic CSI on an unlicensed carrier to anunlicensed cell, where the second portion is less than or equal toremaining portion of the total transmit power after allocating the firstportion to the uplink channel. In an aspect, the apparatus 1202/1202′may further include means for allocating a third portion of the totaltransmit power to a first communication via the licensed carrier and asecond communication via the unlicensed carrier, where the third portionis less than or equal to remaining portion of the total transmit powerafter the allocation of the first portion and the second portion.

The aforementioned means may be one or more of the aforementionedcomponents of the apparatus 1202 and/or the processing system 1314 ofthe apparatus 1202′ configured to perform the functions recited by theaforementioned means. As described supra, the processing system 1314 mayinclude the TX Processor 368, the RX Processor 356, and thecontroller/processor 359. As such, in one configuration, theaforementioned means may be the TX Processor 368, the RX Processor 356,and the controller/processor 359 configured to perform the functionsrecited by the aforementioned means.

It is understood that the specific order or hierarchy of blocks in theprocesses/flowcharts disclosed is an illustration of exemplaryapproaches. Based upon design preferences, it is understood that thespecific order or hierarchy of blocks in the processes/flowcharts may berearranged. Further, some blocks may be combined or omitted. Theaccompanying method claims present elements of the various blocks in asample order, and are not meant to be limited to the specific order orhierarchy presented.

The previous description is provided to enable any person skilled in theart to practice the various aspects described herein. Variousmodifications to these aspects will be readily apparent to those skilledin the art, and the generic principles defined herein may be applied toother aspects. Thus, the claims are not intended to be limited to theaspects shown herein, but is to be accorded the full scope consistentwith the language claims, wherein reference to an element in thesingular is not intended to mean “one and only one” unless specificallyso stated, but rather “one or more.” The word “exemplary” is used hereinto mean “serving as an example, instance, or illustration.” Any aspectdescribed herein as “exemplary” is not necessarily to be construed aspreferred or advantageous over other aspects. Unless specifically statedotherwise, the term “some” refers to one or more. Combinations such as“at least one of A, B, or C,” “one or more of A, B, or C,” “at least oneof A, B, and C,” “one or more of A, B, and C,” and “A, B, C, or anycombination thereof” include any combination of A, B, and/or C, and mayinclude multiples of A, multiples of B, or multiples of C. Specifically,combinations such as “at least one of A, B, or C,” “one or more of A, B,or C,” “at least one of A, B, and C,” “one or more of A, B, and C,” and“A, B, C, or any combination thereof” may be A only, B only, C only, Aand B, A and C, B and C, or A and B and C, where any such combinationsmay contain one or more member or members of A, B, or C. All structuraland functional equivalents to the elements of the various aspectsdescribed throughout this disclosure that are known or later come to beknown to those of ordinary skill in the art are expressly incorporatedherein by reference and are intended to be encompassed by the claims.Moreover, nothing disclosed herein is intended to be dedicated to thepublic regardless of whether such disclosure is explicitly recited inthe claims. The words “module,” “mechanism,” “element,” “device,” andthe like may not be a substitute for the word “means.” As such, no claimelement is to be construed as a means plus function unless the elementis expressly recited using the phrase “means for.”

What is claimed is:
 1. A method of wireless communication by a userequipment (UE) in a shared spectrum, comprising: receiving a grant foruplink communication; determining a reporting subframe based on thegrant; determining a reference subframe, by the UE, from a set ofsubframes from consecutive subframes beginning at a triggering subframein which the grant is received to a subframe before the reportingsubframe; and transmitting, in the reporting subframe, channel stateinformation (CSI) measured in the reference subframe.
 2. The method ofclaim 1, wherein the grant indicates a delay between a reception of thegrant and an uplink transmission, and the reporting subframe isdetermined based on the delay.
 3. The method of claim 1, furthercomprising: receiving a trigger signal indicating a location of thereporting subframe, wherein the reporting subframe is determined basedon the grant and the trigger signal.
 4. The method of claim 1, whereinthe determining the reference subframe is based on a radio resourcecontrol (RRC) signal or a dynamic indication in downlink controlinformation.
 5. The method of claim 1, wherein the subframe before thereporting subframe is located after the triggering subframe.
 6. Themethod of claim 5, wherein the subframe before the reporting subframe islocated at least a predefined number of subframes before the reportingsubframe.
 7. A user equipment (UE) for wireless communication in ashared spectrum, comprising: means for receiving a grant for uplinkcommunication; means for determining a reporting subframe based on thegrant; means for determining a reference subframe, by the UE, from a setof subframes from consecutive subframes beginning at a triggeringsubframe in which the grant is received to a subframe before thereporting subframe; and means for transmitting, in the reportingsubframe, channel state information (CSI) measured in the referencesubframe.
 8. The UE of claim 7, wherein the grant indicates a delaybetween a reception of the grant and an uplink transmission, and thereporting subframe is determined based on the delay.
 9. The UE of claim7, further comprising: means for receiving a trigger signal indicating alocation of the reporting subframe, wherein the means for determiningthe reporting subframe is configured to determine the reporting subframebased on the grant and the trigger signal.
 10. The UE of claim 7,wherein the means for determining whether to select the triggeringsubframe or the subframe before the reporting subframe is configured todetermine whether to select the triggering subframe or the subframebefore the reporting subframe based on a radio resource control (RRC)signal or a dynamic indication in downlink control information.
 11. TheUE of claim 7, wherein the subframe before the reporting subframe islocated after the triggering subframe.
 12. The UE of claim 11, whereinthe subframe before the reporting subframe is located at least apredefined number of subframes before the reporting subframe.
 13. A userequipment (UE) for wireless communication in a shared spectrum,comprising: a memory; and at least one processor coupled to the memoryand configured to: receive a grant for uplink communication; determine areporting subframe based on the grant; determine a reference subframe,by the UE, from a set of subframes from consecutive subframes beginningat a triggering subframe in which the grant is received to a subframebefore the reporting subframe; and transmit, in the reporting subframe,channel state information (CSI) measured in the reference subframe. 14.The UE of claim 13, wherein the grant indicates a delay between areception of the grant and an uplink transmission, and the reportingsubframe is determined based on the delay.
 15. The UE of claim 13,wherein the at least one processor is further configured to: receive atrigger signal indicating a location of the reporting subframe, whereinthe reporting subframe is determined based on the grant and the triggersignal.
 16. The UE of claim 13, wherein the at least one processordetermines whether to select the triggering subframe or the subframebefore the reporting subframe is based on a radio resource control (RRC)signal or a dynamic indication in downlink control information.
 17. TheUE of claim 13, wherein the subframe before the reporting subframe islocated after the triggering subframe.
 18. The UE of claim 17, whereinthe subframe before the reporting subframe is located at least apredefined number of subframes before the reporting subframe.
 19. Anon-transitory computer-readable medium storing computer executablecode, comprising code to: receive a grant for uplink communication;determine a reporting subframe based on the grant; determine a referencesubframe, by the UE, from a set of subframes from consecutive subframesbeginning at a triggering subframe in which the grant is received to asubframe before the reporting subframe; and transmit, in the reportingsubframe, channel state information (CSI) measured in the referencesubframe.